Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[linux-2.6/libata-dev.git] / net / mac80211 / scan.c
blob43a45cf00e06803b091a350694621d87150ee46f
1 /*
2 * Scanning implementation
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/pm_qos.h>
19 #include <net/sch_generic.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <net/mac80211.h>
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
35 if (!bss)
36 return;
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
43 u8 qos_info;
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
51 else
52 /* no valid wmm information or parameter element found */
53 return false;
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
58 struct ieee80211_bss *
59 ieee80211_bss_info_update(struct ieee80211_local *local,
60 struct ieee80211_rx_status *rx_status,
61 struct ieee80211_mgmt *mgmt, size_t len,
62 struct ieee802_11_elems *elems,
63 struct ieee80211_channel *channel)
65 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
66 struct cfg80211_bss *cbss;
67 struct ieee80211_bss *bss;
68 int clen, srlen;
69 s32 signal = 0;
71 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
72 signal = rx_status->signal * 100;
73 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
74 signal = (rx_status->signal * 100) / local->hw.max_signal;
76 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
77 mgmt, len, signal, GFP_ATOMIC);
78 if (!cbss)
79 return NULL;
81 bss = (void *)cbss->priv;
83 if (beacon)
84 bss->device_ts_beacon = rx_status->device_timestamp;
85 else
86 bss->device_ts_presp = rx_status->device_timestamp;
88 if (elems->parse_error) {
89 if (beacon)
90 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
91 else
92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
93 } else {
94 if (beacon)
95 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
96 else
97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 /* save the ERP value so that it is available at association time */
101 if (elems->erp_info && elems->erp_info_len >= 1 &&
102 (!elems->parse_error ||
103 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
104 bss->erp_value = elems->erp_info[0];
105 bss->has_erp_value = true;
106 if (!elems->parse_error)
107 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
110 /* replace old supported rates if we get new values */
111 if (!elems->parse_error ||
112 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
113 srlen = 0;
114 if (elems->supp_rates) {
115 clen = IEEE80211_MAX_SUPP_RATES;
116 if (clen > elems->supp_rates_len)
117 clen = elems->supp_rates_len;
118 memcpy(bss->supp_rates, elems->supp_rates, clen);
119 srlen += clen;
121 if (elems->ext_supp_rates) {
122 clen = IEEE80211_MAX_SUPP_RATES - srlen;
123 if (clen > elems->ext_supp_rates_len)
124 clen = elems->ext_supp_rates_len;
125 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
126 clen);
127 srlen += clen;
129 if (srlen) {
130 bss->supp_rates_len = srlen;
131 if (!elems->parse_error)
132 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
136 if (!elems->parse_error ||
137 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
138 bss->wmm_used = elems->wmm_param || elems->wmm_info;
139 bss->uapsd_supported = is_uapsd_supported(elems);
140 if (!elems->parse_error)
141 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
144 return bss;
147 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
149 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
150 struct ieee80211_sub_if_data *sdata1, *sdata2;
151 struct ieee80211_mgmt *mgmt = (void *)skb->data;
152 struct ieee80211_bss *bss;
153 u8 *elements;
154 struct ieee80211_channel *channel;
155 size_t baselen;
156 bool beacon;
157 struct ieee802_11_elems elems;
159 if (skb->len < 24 ||
160 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
161 !ieee80211_is_beacon(mgmt->frame_control)))
162 return;
164 sdata1 = rcu_dereference(local->scan_sdata);
165 sdata2 = rcu_dereference(local->sched_scan_sdata);
167 if (likely(!sdata1 && !sdata2))
168 return;
170 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
171 /* ignore ProbeResp to foreign address */
172 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
173 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
174 return;
176 elements = mgmt->u.probe_resp.variable;
177 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
178 beacon = false;
179 } else {
180 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
181 elements = mgmt->u.beacon.variable;
182 beacon = true;
185 if (baselen > skb->len)
186 return;
188 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
190 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
192 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
193 return;
195 bss = ieee80211_bss_info_update(local, rx_status,
196 mgmt, skb->len, &elems,
197 channel);
198 if (bss)
199 ieee80211_rx_bss_put(local, bss);
202 /* return false if no more work */
203 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
205 struct cfg80211_scan_request *req = local->scan_req;
206 enum ieee80211_band band;
207 int i, ielen, n_chans;
209 do {
210 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
211 return false;
213 band = local->hw_scan_band;
214 n_chans = 0;
215 for (i = 0; i < req->n_channels; i++) {
216 if (req->channels[i]->band == band) {
217 local->hw_scan_req->channels[n_chans] =
218 req->channels[i];
219 n_chans++;
223 local->hw_scan_band++;
224 } while (!n_chans);
226 local->hw_scan_req->n_channels = n_chans;
228 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
229 local->hw_scan_ies_bufsize,
230 req->ie, req->ie_len, band,
231 req->rates[band], 0);
232 local->hw_scan_req->ie_len = ielen;
233 local->hw_scan_req->no_cck = req->no_cck;
235 return true;
238 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
239 bool was_hw_scan)
241 struct ieee80211_local *local = hw_to_local(hw);
243 lockdep_assert_held(&local->mtx);
246 * It's ok to abort a not-yet-running scan (that
247 * we have one at all will be verified by checking
248 * local->scan_req next), but not to complete it
249 * successfully.
251 if (WARN_ON(!local->scanning && !aborted))
252 aborted = true;
254 if (WARN_ON(!local->scan_req))
255 return;
257 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
258 int rc;
260 rc = drv_hw_scan(local,
261 rcu_dereference_protected(local->scan_sdata,
262 lockdep_is_held(&local->mtx)),
263 local->hw_scan_req);
265 if (rc == 0)
266 return;
269 kfree(local->hw_scan_req);
270 local->hw_scan_req = NULL;
272 if (local->scan_req != local->int_scan_req)
273 cfg80211_scan_done(local->scan_req, aborted);
274 local->scan_req = NULL;
275 rcu_assign_pointer(local->scan_sdata, NULL);
277 local->scanning = 0;
278 local->scan_channel = NULL;
280 /* Set power back to normal operating levels. */
281 ieee80211_hw_config(local, 0);
283 if (!was_hw_scan) {
284 ieee80211_configure_filter(local);
285 drv_sw_scan_complete(local);
286 ieee80211_offchannel_return(local);
289 ieee80211_recalc_idle(local);
291 ieee80211_mlme_notify_scan_completed(local);
292 ieee80211_ibss_notify_scan_completed(local);
293 ieee80211_mesh_notify_scan_completed(local);
294 ieee80211_start_next_roc(local);
297 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
299 struct ieee80211_local *local = hw_to_local(hw);
301 trace_api_scan_completed(local, aborted);
303 set_bit(SCAN_COMPLETED, &local->scanning);
304 if (aborted)
305 set_bit(SCAN_ABORTED, &local->scanning);
306 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
308 EXPORT_SYMBOL(ieee80211_scan_completed);
310 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
312 /* Software scan is not supported in multi-channel cases */
313 if (local->use_chanctx)
314 return -EOPNOTSUPP;
317 * Hardware/driver doesn't support hw_scan, so use software
318 * scanning instead. First send a nullfunc frame with power save
319 * bit on so that AP will buffer the frames for us while we are not
320 * listening, then send probe requests to each channel and wait for
321 * the responses. After all channels are scanned, tune back to the
322 * original channel and send a nullfunc frame with power save bit
323 * off to trigger the AP to send us all the buffered frames.
325 * Note that while local->sw_scanning is true everything else but
326 * nullfunc frames and probe requests will be dropped in
327 * ieee80211_tx_h_check_assoc().
329 drv_sw_scan_start(local);
331 local->leave_oper_channel_time = jiffies;
332 local->next_scan_state = SCAN_DECISION;
333 local->scan_channel_idx = 0;
335 ieee80211_offchannel_stop_vifs(local);
337 /* ensure nullfunc is transmitted before leaving operating channel */
338 drv_flush(local, false);
340 ieee80211_configure_filter(local);
342 /* We need to set power level at maximum rate for scanning. */
343 ieee80211_hw_config(local, 0);
345 ieee80211_queue_delayed_work(&local->hw,
346 &local->scan_work, 0);
348 return 0;
351 static bool ieee80211_can_scan(struct ieee80211_local *local,
352 struct ieee80211_sub_if_data *sdata)
354 if (local->radar_detect_enabled)
355 return false;
357 if (!list_empty(&local->roc_list))
358 return false;
360 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
361 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
362 IEEE80211_STA_CONNECTION_POLL))
363 return false;
365 return true;
368 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
370 lockdep_assert_held(&local->mtx);
372 if (!local->scan_req || local->scanning)
373 return;
375 if (!ieee80211_can_scan(local,
376 rcu_dereference_protected(
377 local->scan_sdata,
378 lockdep_is_held(&local->mtx))))
379 return;
381 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
382 round_jiffies_relative(0));
385 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
386 unsigned long *next_delay)
388 int i;
389 struct ieee80211_sub_if_data *sdata;
390 enum ieee80211_band band = local->hw.conf.channel->band;
391 u32 tx_flags;
393 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
394 if (local->scan_req->no_cck)
395 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
397 sdata = rcu_dereference_protected(local->scan_sdata,
398 lockdep_is_held(&local->mtx));
400 for (i = 0; i < local->scan_req->n_ssids; i++)
401 ieee80211_send_probe_req(
402 sdata, NULL,
403 local->scan_req->ssids[i].ssid,
404 local->scan_req->ssids[i].ssid_len,
405 local->scan_req->ie, local->scan_req->ie_len,
406 local->scan_req->rates[band], false,
407 tx_flags, local->hw.conf.channel, true);
410 * After sending probe requests, wait for probe responses
411 * on the channel.
413 *next_delay = IEEE80211_CHANNEL_TIME;
414 local->next_scan_state = SCAN_DECISION;
417 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
418 struct cfg80211_scan_request *req)
420 struct ieee80211_local *local = sdata->local;
421 int rc;
423 lockdep_assert_held(&local->mtx);
425 if (local->scan_req)
426 return -EBUSY;
428 if (!ieee80211_can_scan(local, sdata)) {
429 /* wait for the work to finish/time out */
430 local->scan_req = req;
431 rcu_assign_pointer(local->scan_sdata, sdata);
432 return 0;
435 if (local->ops->hw_scan) {
436 u8 *ies;
438 local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN +
439 local->scan_ies_len +
440 req->ie_len;
441 local->hw_scan_req = kmalloc(
442 sizeof(*local->hw_scan_req) +
443 req->n_channels * sizeof(req->channels[0]) +
444 local->hw_scan_ies_bufsize, GFP_KERNEL);
445 if (!local->hw_scan_req)
446 return -ENOMEM;
448 local->hw_scan_req->ssids = req->ssids;
449 local->hw_scan_req->n_ssids = req->n_ssids;
450 ies = (u8 *)local->hw_scan_req +
451 sizeof(*local->hw_scan_req) +
452 req->n_channels * sizeof(req->channels[0]);
453 local->hw_scan_req->ie = ies;
454 local->hw_scan_req->flags = req->flags;
456 local->hw_scan_band = 0;
459 * After allocating local->hw_scan_req, we must
460 * go through until ieee80211_prep_hw_scan(), so
461 * anything that might be changed here and leave
462 * this function early must not go after this
463 * allocation.
467 local->scan_req = req;
468 rcu_assign_pointer(local->scan_sdata, sdata);
470 if (local->ops->hw_scan) {
471 __set_bit(SCAN_HW_SCANNING, &local->scanning);
472 } else if ((req->n_channels == 1) &&
473 (req->channels[0] == local->_oper_channel)) {
475 * If we are scanning only on the operating channel
476 * then we do not need to stop normal activities
478 unsigned long next_delay;
480 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
482 ieee80211_recalc_idle(local);
484 /* Notify driver scan is starting, keep order of operations
485 * same as normal software scan, in case that matters. */
486 drv_sw_scan_start(local);
488 ieee80211_configure_filter(local); /* accept probe-responses */
490 /* We need to ensure power level is at max for scanning. */
491 ieee80211_hw_config(local, 0);
493 if ((req->channels[0]->flags &
494 IEEE80211_CHAN_PASSIVE_SCAN) ||
495 !local->scan_req->n_ssids) {
496 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
497 } else {
498 ieee80211_scan_state_send_probe(local, &next_delay);
499 next_delay = IEEE80211_CHANNEL_TIME;
502 /* Now, just wait a bit and we are all done! */
503 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
504 next_delay);
505 return 0;
506 } else {
507 /* Do normal software scan */
508 __set_bit(SCAN_SW_SCANNING, &local->scanning);
511 ieee80211_recalc_idle(local);
513 if (local->ops->hw_scan) {
514 WARN_ON(!ieee80211_prep_hw_scan(local));
515 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
516 } else
517 rc = ieee80211_start_sw_scan(local);
519 if (rc) {
520 kfree(local->hw_scan_req);
521 local->hw_scan_req = NULL;
522 local->scanning = 0;
524 ieee80211_recalc_idle(local);
526 local->scan_req = NULL;
527 rcu_assign_pointer(local->scan_sdata, NULL);
530 return rc;
533 static unsigned long
534 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
537 * TODO: channel switching also consumes quite some time,
538 * add that delay as well to get a better estimation
540 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
541 return IEEE80211_PASSIVE_CHANNEL_TIME;
542 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
545 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
546 unsigned long *next_delay)
548 bool associated = false;
549 bool tx_empty = true;
550 bool bad_latency;
551 struct ieee80211_sub_if_data *sdata;
552 struct ieee80211_channel *next_chan;
553 enum mac80211_scan_state next_scan_state;
556 * check if at least one STA interface is associated,
557 * check if at least one STA interface has pending tx frames
558 * and grab the lowest used beacon interval
560 mutex_lock(&local->iflist_mtx);
561 list_for_each_entry(sdata, &local->interfaces, list) {
562 if (!ieee80211_sdata_running(sdata))
563 continue;
565 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
566 if (sdata->u.mgd.associated) {
567 associated = true;
569 if (!qdisc_all_tx_empty(sdata->dev)) {
570 tx_empty = false;
571 break;
576 mutex_unlock(&local->iflist_mtx);
578 next_chan = local->scan_req->channels[local->scan_channel_idx];
581 * we're currently scanning a different channel, let's
582 * see if we can scan another channel without interfering
583 * with the current traffic situation.
585 * Keep good latency, do not stay off-channel more than 125 ms.
588 bad_latency = time_after(jiffies +
589 ieee80211_scan_get_channel_time(next_chan),
590 local->leave_oper_channel_time + HZ / 8);
592 if (associated && !tx_empty) {
593 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
594 next_scan_state = SCAN_ABORT;
595 else
596 next_scan_state = SCAN_SUSPEND;
597 } else if (associated && bad_latency) {
598 next_scan_state = SCAN_SUSPEND;
599 } else {
600 next_scan_state = SCAN_SET_CHANNEL;
603 local->next_scan_state = next_scan_state;
605 *next_delay = 0;
608 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
609 unsigned long *next_delay)
611 int skip;
612 struct ieee80211_channel *chan;
614 skip = 0;
615 chan = local->scan_req->channels[local->scan_channel_idx];
617 local->scan_channel = chan;
619 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
620 skip = 1;
622 /* advance state machine to next channel/band */
623 local->scan_channel_idx++;
625 if (skip) {
626 /* if we skip this channel return to the decision state */
627 local->next_scan_state = SCAN_DECISION;
628 return;
632 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
633 * (which unfortunately doesn't say _why_ step a) is done,
634 * but it waits for the probe delay or until a frame is
635 * received - and the received frame would update the NAV).
636 * For now, we do not support waiting until a frame is
637 * received.
639 * In any case, it is not necessary for a passive scan.
641 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
642 !local->scan_req->n_ssids) {
643 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
644 local->next_scan_state = SCAN_DECISION;
645 return;
648 /* active scan, send probes */
649 *next_delay = IEEE80211_PROBE_DELAY;
650 local->next_scan_state = SCAN_SEND_PROBE;
653 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
654 unsigned long *next_delay)
656 /* switch back to the operating channel */
657 local->scan_channel = NULL;
658 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
660 /* disable PS */
661 ieee80211_offchannel_return(local);
663 *next_delay = HZ / 5;
664 /* afterwards, resume scan & go to next channel */
665 local->next_scan_state = SCAN_RESUME;
668 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
669 unsigned long *next_delay)
671 ieee80211_offchannel_stop_vifs(local);
673 if (local->ops->flush) {
674 drv_flush(local, false);
675 *next_delay = 0;
676 } else
677 *next_delay = HZ / 10;
679 /* remember when we left the operating channel */
680 local->leave_oper_channel_time = jiffies;
682 /* advance to the next channel to be scanned */
683 local->next_scan_state = SCAN_SET_CHANNEL;
686 void ieee80211_scan_work(struct work_struct *work)
688 struct ieee80211_local *local =
689 container_of(work, struct ieee80211_local, scan_work.work);
690 struct ieee80211_sub_if_data *sdata;
691 unsigned long next_delay = 0;
692 bool aborted, hw_scan;
694 mutex_lock(&local->mtx);
696 sdata = rcu_dereference_protected(local->scan_sdata,
697 lockdep_is_held(&local->mtx));
699 /* When scanning on-channel, the first-callback means completed. */
700 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
701 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
702 goto out_complete;
705 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
706 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
707 goto out_complete;
710 if (!sdata || !local->scan_req)
711 goto out;
713 if (local->scan_req && !local->scanning) {
714 struct cfg80211_scan_request *req = local->scan_req;
715 int rc;
717 local->scan_req = NULL;
718 rcu_assign_pointer(local->scan_sdata, NULL);
720 rc = __ieee80211_start_scan(sdata, req);
721 if (rc) {
722 /* need to complete scan in cfg80211 */
723 local->scan_req = req;
724 aborted = true;
725 goto out_complete;
726 } else
727 goto out;
731 * Avoid re-scheduling when the sdata is going away.
733 if (!ieee80211_sdata_running(sdata)) {
734 aborted = true;
735 goto out_complete;
739 * as long as no delay is required advance immediately
740 * without scheduling a new work
742 do {
743 if (!ieee80211_sdata_running(sdata)) {
744 aborted = true;
745 goto out_complete;
748 switch (local->next_scan_state) {
749 case SCAN_DECISION:
750 /* if no more bands/channels left, complete scan */
751 if (local->scan_channel_idx >= local->scan_req->n_channels) {
752 aborted = false;
753 goto out_complete;
755 ieee80211_scan_state_decision(local, &next_delay);
756 break;
757 case SCAN_SET_CHANNEL:
758 ieee80211_scan_state_set_channel(local, &next_delay);
759 break;
760 case SCAN_SEND_PROBE:
761 ieee80211_scan_state_send_probe(local, &next_delay);
762 break;
763 case SCAN_SUSPEND:
764 ieee80211_scan_state_suspend(local, &next_delay);
765 break;
766 case SCAN_RESUME:
767 ieee80211_scan_state_resume(local, &next_delay);
768 break;
769 case SCAN_ABORT:
770 aborted = true;
771 goto out_complete;
773 } while (next_delay == 0);
775 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
776 goto out;
778 out_complete:
779 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
780 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
781 out:
782 mutex_unlock(&local->mtx);
785 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
786 struct cfg80211_scan_request *req)
788 int res;
790 mutex_lock(&sdata->local->mtx);
791 res = __ieee80211_start_scan(sdata, req);
792 mutex_unlock(&sdata->local->mtx);
794 return res;
797 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
798 const u8 *ssid, u8 ssid_len,
799 struct ieee80211_channel *chan)
801 struct ieee80211_local *local = sdata->local;
802 int ret = -EBUSY;
803 enum ieee80211_band band;
805 mutex_lock(&local->mtx);
807 /* busy scanning */
808 if (local->scan_req)
809 goto unlock;
811 /* fill internal scan request */
812 if (!chan) {
813 int i, max_n;
814 int n_ch = 0;
816 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
817 if (!local->hw.wiphy->bands[band])
818 continue;
820 max_n = local->hw.wiphy->bands[band]->n_channels;
821 for (i = 0; i < max_n; i++) {
822 struct ieee80211_channel *tmp_ch =
823 &local->hw.wiphy->bands[band]->channels[i];
825 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS |
826 IEEE80211_CHAN_DISABLED))
827 continue;
829 local->int_scan_req->channels[n_ch] = tmp_ch;
830 n_ch++;
834 if (WARN_ON_ONCE(n_ch == 0))
835 goto unlock;
837 local->int_scan_req->n_channels = n_ch;
838 } else {
839 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS |
840 IEEE80211_CHAN_DISABLED)))
841 goto unlock;
843 local->int_scan_req->channels[0] = chan;
844 local->int_scan_req->n_channels = 1;
847 local->int_scan_req->ssids = &local->scan_ssid;
848 local->int_scan_req->n_ssids = 1;
849 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
850 local->int_scan_req->ssids[0].ssid_len = ssid_len;
852 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
853 unlock:
854 mutex_unlock(&local->mtx);
855 return ret;
859 * Only call this function when a scan can't be queued -- under RTNL.
861 void ieee80211_scan_cancel(struct ieee80211_local *local)
864 * We are canceling software scan, or deferred scan that was not
865 * yet really started (see __ieee80211_start_scan ).
867 * Regarding hardware scan:
868 * - we can not call __ieee80211_scan_completed() as when
869 * SCAN_HW_SCANNING bit is set this function change
870 * local->hw_scan_req to operate on 5G band, what race with
871 * driver which can use local->hw_scan_req
873 * - we can not cancel scan_work since driver can schedule it
874 * by ieee80211_scan_completed(..., true) to finish scan
876 * Hence we only call the cancel_hw_scan() callback, but the low-level
877 * driver is still responsible for calling ieee80211_scan_completed()
878 * after the scan was completed/aborted.
881 mutex_lock(&local->mtx);
882 if (!local->scan_req)
883 goto out;
885 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
886 if (local->ops->cancel_hw_scan)
887 drv_cancel_hw_scan(local,
888 rcu_dereference_protected(local->scan_sdata,
889 lockdep_is_held(&local->mtx)));
890 goto out;
894 * If the work is currently running, it must be blocked on
895 * the mutex, but we'll set scan_sdata = NULL and it'll
896 * simply exit once it acquires the mutex.
898 cancel_delayed_work(&local->scan_work);
899 /* and clean up */
900 __ieee80211_scan_completed(&local->hw, true, false);
901 out:
902 mutex_unlock(&local->mtx);
905 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
906 struct cfg80211_sched_scan_request *req)
908 struct ieee80211_local *local = sdata->local;
909 struct ieee80211_sched_scan_ies sched_scan_ies = {};
910 int ret, i, iebufsz;
912 iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
913 local->scan_ies_len + req->ie_len;
915 mutex_lock(&local->mtx);
917 if (rcu_access_pointer(local->sched_scan_sdata)) {
918 ret = -EBUSY;
919 goto out;
922 if (!local->ops->sched_scan_start) {
923 ret = -ENOTSUPP;
924 goto out;
927 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
928 if (!local->hw.wiphy->bands[i])
929 continue;
931 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
932 if (!sched_scan_ies.ie[i]) {
933 ret = -ENOMEM;
934 goto out_free;
937 sched_scan_ies.len[i] =
938 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
939 iebufsz, req->ie, req->ie_len,
940 i, (u32) -1, 0);
943 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
944 if (ret == 0)
945 rcu_assign_pointer(local->sched_scan_sdata, sdata);
947 out_free:
948 while (i > 0)
949 kfree(sched_scan_ies.ie[--i]);
950 out:
951 mutex_unlock(&local->mtx);
952 return ret;
955 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
957 struct ieee80211_local *local = sdata->local;
958 int ret = 0;
960 mutex_lock(&local->mtx);
962 if (!local->ops->sched_scan_stop) {
963 ret = -ENOTSUPP;
964 goto out;
967 if (rcu_access_pointer(local->sched_scan_sdata))
968 drv_sched_scan_stop(local, sdata);
970 out:
971 mutex_unlock(&local->mtx);
973 return ret;
976 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
978 struct ieee80211_local *local = hw_to_local(hw);
980 trace_api_sched_scan_results(local);
982 cfg80211_sched_scan_results(hw->wiphy);
984 EXPORT_SYMBOL(ieee80211_sched_scan_results);
986 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
988 struct ieee80211_local *local =
989 container_of(work, struct ieee80211_local,
990 sched_scan_stopped_work);
992 mutex_lock(&local->mtx);
994 if (!rcu_access_pointer(local->sched_scan_sdata)) {
995 mutex_unlock(&local->mtx);
996 return;
999 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1001 mutex_unlock(&local->mtx);
1003 cfg80211_sched_scan_stopped(local->hw.wiphy);
1006 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1008 struct ieee80211_local *local = hw_to_local(hw);
1010 trace_api_sched_scan_stopped(local);
1012 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1014 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);